Determination of Aprotinin (BPTI)

Hello:
I have to determine aprotinin (Bovine pancreatic trypsin inhibitor), and I
have found several techniques that use trypsin-Sepharose 4b or
Kallikrein-Sepharose 4b to bound and purify the aprotinin.
I haven´t found trypsin-Sepharose 4b or Kallikrein-Sepharose 4b in Spain.
I hope you can help me to found the maker of this sepharose or another
technique to determine aprotinine in a UV-HPLC system.
Best regards
Chema